Building lath



Feb. 14, 1939. E. WESTBERG 2,146,782

BUILDING LA-TH FiledJan. 4, 1937 INVENTOR. GUJZQVEE WE5T5ER6 ATTORNEYS.

Patented Feb. 14, 1939 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to building construction, and particularly pertains to a lath.

In the use of wooden lath in providing a background and support for plaster it has been found that the moisture in the plaster tends to enter the lath and cause it to buckle between its fixed supports. This in turn eventually causes the plasterto become undulated, and in some instances to crack and become separated from the lath. In Patent No. 2,038,173, issued to Harlow H. Hathaway on April 21, 1936, a lath is disclosed in which the longitudinal grain of the lath has been broken at intervals throughout its length and by serrations and indentations separately staggered and extending part way across the face of the lath. In this particular lath a V-shaped groove has been cut lengthwise of the edge of the lath to facilitate in making a plaster board. It has been found, however, that there is an objectionable amount of loss of plaster through the space between the lath, as took place in the old and common form, and that furthermore the feathered edges formed by the groove in the edge of the lath have a decided tendency to buckle and to thus create cracks in the plaster and uneven surface areas on the finished wall. It is the principal object. of the present invention therefor to provide a wood lath which may be applied to wall and ceiling studding in the usual manner and which will act to eliminate all characteristics of the lath tending to cause it to buckle, and furthermore which provides proper spacing between the lath and a perfect bond with the plaster applied thereover, the lath being so arranged as to insure that there will be no waste of plaster whatsoever when plaster is applied to the lath surface.

The invention is illustrated by way of example in the accompanying drawing in which:

Figure 1 is a view in perspective showing the use of lath with which the particular invention is concerned, and particularly demonstrating the manner in which a bond is created between the lath edges and the plaster, and whereby the waste of plaster will be eliminated.

Fig. 2 is a view in elevation showing a portion of the length of lath, and further disclosing the manner in which the longitudinal grain of the lath is broken so that swelling of the lath will not cause it to buckle.

Fig. 3 is an enlarged View through the lath as seen on the line 3-3 of Fig. 2 showing the manner in which the grain in the feathered edge of the lath is broken to prevent buckling.

Fig. 4 is an enlarged view in transverse section as seen on the line 4-4 of Fig. 2.showing the manner in which the grain of the wood in the body of the lath is broken.

Referring more particularly to the drawing, I indicates a lath having a back face I l and a front face l2. Longitudinal marginal edges are formed having a short face l3 and a long face It. These faces are disposed at right angles to each other and due to their arrangement it will be seen that the width of the back face I l of the lath is greater than the width of the front face 12. When two of the laths are laid parallel with their grooved edges adjacent to each other, as shown in Fig. 1 of the drawing, it will be seen that a substantially diamond-shaped groove I5 will be formed having an opened throat l6 bounded on opposite sides by the inclined faces l3 of the grooves, while the faces l4 of the grooves will converge so that the contiguous edges I1 of the faces ll will substantially meet and close the back of the groove l5. Thus it will be possible for the plaster indicated at l8 to fill the groove l5 and to make a positive bond therewith. The lath is slit at points along its edges as indicated at l9. These slits extend transversely of the length of the lath and are of a depth suificient to extend entirely through the. lath and to break the grain of the feathered edge II, as well as the feathered edge 20. Extending transversely of the lath and in staggered relation to each other are indentations or slits 2|. These may pass entirely through the lath as indicated at the top of Fig. 4 of the drawing, or they may be in the form of indentations or dents made in the surface of the facee l l and I2 of the laths so that the longitudinal grain of the lath will be broken at intervals throughout the length of the lath. These indentations or perforations are preferably of a length materially less than the width of the lath so that the lath will not be weakened in a straight line entirely across its face. Indentations are therefore staggered with relation to each other so thatthe grain will be recurrently broken at predetermined intervals throughout the length of the lath body and so that the longitudinal grain of the lath in the feathered portions will be broken at intervals throughout the length thereof.

In the use of the lath here shown the separate laths are nailed to suitable studdings with their feathered edges l'l abutting as shown in Fig. 1. This closes the groove I5 which is formed by the inclined faces l3 and I4 along the lath edges. The plaster I8 is then applied to the faces l2 of the lath as shown in Fig. l and the plaster will be forced into the grooves l5 to form a key therewith when the plaster is hard. Attention is directed to the fact that the laths are not spaced with their contiguous edges apart as has been common practice, since this arrangement would allow a quantity of plaster to be forced between the laths and to be wasted in the wall space between the studdings. When the wet plaster is applied it is evident that the lath will to a certain extent absorb the moisture from the plaster and that the grain in the lath will have a tendency to swell. By the old method of applying lath with spaces between them lateral swelling could be accommodated, but longitudinal swelling will result in buckling. In the present instance lateral swelling will be accommodated by the breaks in the longitudinal grain formed by the serrations. I9 which are formed through the feathered edges I1 and 20 of the lath. This will permit the contiguous edges I! to adjust themselves so that buckling action along the edges of the lath will be eliminated. Indentations or perforations 2| which have broken the grain of the lath at difierent points in its length will prevent buckling of the body of the lath.

It will thus be seen that the wall structure formed with the invention here disclosed provides a base which will not buckle or warp, will also provide a more perfect plaster bond than is now possible, and will insure that a rigid wall will be formed using a minimum amount of plaster and affording a maximum protection against vibration and damage to the plaster carried thereby.

While I have shown the preferred form of my invention, as now known to me, it will be understood that various changes might be made in the combination, construction, and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as, claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A wooden lath formed with continuous longitudinal grooves along its opposite edges, the grain of the lath along said grooves being broken at intervals throughout the length of the lath.

2. A wooden. lath formed with opposite plane faces and with continuous V-shaped grooves along their opposite edges, said grooves being formed with a relatively narrow face and a relatively wide face whereby lathsplaced parallel to each other and abutting along an edge will form a substantially diamond-shaped groove, said edges being broken at intervals along their longitudinal length'by transverse serrations.

GUSTAVE EDWARD WESTBERG. 

